The present invention relates to a steering lock for engaging a lock bar with a steering shaft to disable steering.
Japanese Laid-Open Patent Publication No. 2003-063354, describes a conventional electric steering lock. The conventional electric steering lock includes an actuator such as a motor that is powered when a mechanical key, which is inserted in a key cylinder, is turned. A steering shaft is locked by a lock bar driven by the actuator.
The steering lock includes a housing and a bracket, which are attached to a sleeve covering the steering shaft. The sleeve is held between the housing and the bracket. A bolt fastens the housing and the bracket to fix the housing to the sleeve.
The housing houses various internal components. The internal components include the lock bar, which is movable for engagement with the steering shaft, a motor for driving the lock bar, a transmission mechanism for transmitting the drive force of the motor to the lock bar, a steering lock electronic control unit (ECU) for controlling the motor, and lock and unlock switches for detecting whether the lock bar is engaged with the steering shaft.
Each internal component is inserted in the housing from an opening of the housing and arranged at a predetermined position in the housing. A cover is attached to the housing to close the opening. The steering lock disables steering to prevent theft of an automobile provided with the steering lock.
The transmission mechanism includes a worm gear rotated integrally with an output shaft of the motor, a helical gear meshed with the worm gear, a rotary shaft rotated integrally with the helical gear, an engagement member coupled to and moved along the rotary shaft, a lock bar carrier supported by and moved integrally with the engagement member, a lock bar supported by the lock bar carrier, and a spring compressed between the lock bar and the lock bar carrier. In this manner, the transmission mechanism is assembled from a plurality of components. Thus, the conventional steering requires much time and effort to assemble.